This invention comprises an improvement over balanced steerable power transmissions disclosed in my U.S. Pat. Nos. 3,750,616 and 3,851,614.
In the steerable transmissions of the above-identified patents there are input and output shafts with the output shaft mounted in a housing which is steerable. This permits the direction of the output shaft to be changed independently of the direction of the input shaft. Such an arrangement can be used, for example, for steering a boat, thereby gaining benefits of both an inboard and an outboard arrangement. These transmissions can be somewhat cumbersome and have appreciable drag since a large housing is rotated.
It is desirable to provide an arrangement where the transmission housing is essentially fixed and a steerable yoke or the like can be pivoted about an axis coaxial with the output shaft. This permits a relatively smaller structure to be pivoted. It is desirable that the yoke be steerable with substantially no net torque; that is, with essentially the same torque required to pivot the yoke in either direction, regardless of the direction or speed of rotation of the output shaft.
This not only makes the steerable transmission quite suitable for use in small boats, it can significantly increase the fields in which the transmission is useful. It can be employed in land and air vehicles, construction equipment, wind generators, and a broad variety of other applications limited only by the ingenuity of the user.